How to Fix Blossom End Rot On your Tomatoes

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Last Updated on December 26, 2022

One common problem you would encounter in your tomato garden is a rot at the blossom end of the fruit. It would be best to prevent the bottom of your tomatoes from rotting, but once it has started, with simple measures, you can prevent it from happening again on the same plant. 

So if you are asking how do I fix blossom end rot on my tomatoes, you have come to the right place. Before I get into all the details of how best to improve your plant’s harvest, lets first find out what causes blossom end rot on a tomato plant. 

What is Blossom End Rot?

Most gardeners think that an insect or disease problem causes a blossom end rot; when it is an anomaly that occurs as a result of inadequate uptake of Calcium by the plant’s fruits and leaves. You mustn’t confuse this for calcium deficiency in the soil, as there are several reasons why the fruits and leaves may not be getting the required amount of Calcium to support healthy fruiting. 

How to Fix Blossom End Rot On your Tomatoes

The reason for a discolored patch beneath the fruit could be in the flowering stage when leaves and fruits are competing for Calcium to aid in their development. While using slake lime and adding Calcium to the soil may help in restoring the mineral content of the earth, there are other tricks you can use to stop future occurrences. 

Why your Tomatoes are not Receiving Calcium 

If, after performing a soil test, and you find the calcium content of your soil to be just fine, you may find it challenging to know what exactly is happening in your garden. In most cases, your tomatoes will suffer from nutrient uptake problems when:

  • The pH of the soil is low, thereby causing nutrient absorption problems
  • There is excess nitrogen application resulting in poor nutrient uptake
  • There is no enough water for the absorption of nutrients due to inconsistent watering. 

How to Fix Blossom End Rot On Tomatoes? 

You can follow any of the following methods outlined below if you notice the bottom of your fruits is darker than usual. 

Keep Tabs on Nitrogen Application 

While your plants need to get the right supply of nitrogen, you want to make sure you do not apply more than necessary. When too much of the nutrient is in the soil, it encourages the growth of leaves while making it hard for the fruits to get enough. If you apply fertilizer before planting, ensure you use a balanced feed and avoid applying them at the peak of summer when plants are likely to go into dormancy.   

Don’t Allow the Plants Go Thirsty.

You should keep a watering schedule for your garden plant and stick to it. If you want your plants to be able to absorb nutrients properly, then you need to ensure the earth remains fertile. If you use an irrigation system in your garden, you would want to water deeply but less frequently so as not to waterlog the ground. Also, if you are using a container, you will need to water regularly, and it is best to use soaker hoses or drip watering instead of a foliar application for your tomatoes. 

Mulch your Plants 

Using organic mulch around your plant can help improve moisture retention. You don’t need to use too much; about three-inch of mulch is enough to get the job done. The standard mulch you can use is straw since it is readily available and can last a while. If you also have a weed problem in your garden, mulching will also get rid of it. 

Stay Clear of the Plant Roots During Flowering 

It is also necessary that you do not disturb the plant root once it starts to fruit. You will have to take extra care when weeding or to mulch your plant so as not to stress the soil. When there is too much activity on the earth, it can affect how the root absorbs nutrients. It is common during hot and dry weather for plant roots to undergo stress, which is why you need to water regularly. 

Use the Right Fertilizer for Soil Amendments 

If you need to amend the soil after performing a soil test, you should endeavor to use the right fertilizer in your garden. It is common to find substandard products in the market, so you want to do your research to make sure you end up with the best one. I recommend organic fertilizers always since they do not contain chemical compounds that can be harmful to you, your plants, and the environment. 

Before Planting 

If you are preparing to plant tomatoes in the planting season, you can prevent bottom end rot by using compost rich in Calcium to improve your soil nutrient. Another way is if you are using a container, to use a well-balanced potting soil, so plants don’t suffer from any deficiency as they flower. 


What is tomato end rot?

Blossoms end rot is caused by a soilborne fungus called Botrytis cinerea (Bc). This is a relatively common fungus in the summer and fall months, and is the main reason why tomato plants are pruned off when they flower.

It usually starts out as a small, dark spot or a bump that enlarges.

Can you reverse blossom end rot on tomatoes?

There are many factors that can cause blossom end rot in tomatoes. The two most common factors I see are too much nitrogen and insufficient calcium. If your soil pH is more than 2.2 you will need to adjust your soil pH to 3. The best way to do this is with lime.

You can add 1/4 cup of quicklime per 10 gallons of water or mix 1/4 cup of calcium carbonate in a bucket of water until it is dissolved. Then pour the solution on top of your soil, let it sit for an hour or two, then rake it into your garden bed.

You can spray for blossom end rot with a foliar application of Bordeaux mix. There are many products available for controlling tomato leaf spot, including systemic fungicides, like Mancozeb and Captan.

How do I keep my tomatoes from rotting on the bottom?

Tomatoes are a warm-weather crop that require consistent temperatures of at least 70 degrees for a long period of time. If your garden is not in a greenhouse or covered with shade cloth, you will need to use a high tunnel to protect your plants and fruit. High tunnels are growing houses made of transparent plastic.

They are available in many shapes and sizes and can be purchased from many different companies. Most high tunnels have an insulated floor and a roof that comes down to ground level. Growers who are growing tomatoes in full sun should consider using a high tunnel. You will need to provide ventilation if you are growing tomatoes in a high tunnel. The best way to ventilate is to leave the lid slightly open.

What is a good source of calcium for tomatoes?

Calcium is an essential nutrient needed for the growth and development of all parts of the plant. Calcium helps the plant resist cold and drought stress.

Calcium chloride is often used as an effective foliar fertilizer, but also as a soil drench. Calcium chloride is a water soluble form of calcium. Calcium chloride is used to increase the uptake of nutrients by plants in soils deficient in calcium and other elements. It is also used to lower the pH in acidic soils.

After Planting

Water regularly and use a rich mulch to improve moisture retention. Tomatoes require enough Calcium and would only be able to absorb it from the soil when it is moist.

As soon as you notice any discolored fruits, you should immediately remove them so as they can stop competing for nutrients with the healthy ones. If you have a backyard compost pile, you can add rotten fruits to it to improve the green materials in the mix. 

How to Fix Blossom End Rot On your Tomatoes?

It is also worth mentioning that there are varieties of tomato seeds that are resistant to bottom end rot, so you may want to consider getting those for the next planting season if you do not wish to suffer from the condition. You should also be aware that the rot does not spread amongst the fruits, as it is not a viral disease. It is only a condition that reduces your yield when it is time for harvest. 

Do you grow tomatoes in your garden? Have you ever had to deal with bottom end rot? We will like to hear from you in the comment section. 

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